Process of making phenylglycin-ortho-carboxylic acid.



UNITED STATES EEICE.

PATENT BENNO HOMOLKA, oF FRANKFORT-ON-THE-MAIN, AND FRIEDRICH EUR- NER,0F HoCHsr-oN-TIIE-MAIN, GERMANY, AssIeNoRs TO FARB- wERKE, voRM.MEIsTER, LUOIUS a BRUNING, 0F HOCHST-ON-THE- MAIN, GERMANY.

PROCESS OF MAKING PHENYLGLYCIN*ORTHO-CARBOXYLlC ACID.

SIPECIFIGATION formingpart of Letters Patent No. 675,217, dated May 28,1901.

Application filed March 12, 1901. Serial No. 50,783. (No specimens.)

To all whom it may concern.-

Be it known that we, BENNO HOMOLKA, Ph.D., residing atFrankfort-on-the-Main, and FRIEDRICH HiiBNER, Ph. D., residing atHochst-on-the-Main, in the Empire of Germany, citizens of the Empire ofGermany, have invented certain .new and useful Improvements in theManufacture of Phenylglycin-Ortho-Carboxylic Acid, of which thefollowing is a specification.

Our process to manufacture phenylglyclnortho-carboxylic acid consists inheating mixtures of glycocol'-that is to say, amidoacetic acid-andortho-halogen-benzoic acidthat is to say, ortho-chloro-benzoic acid ororthobrombenz'oic acid--both compounds preferably in form of theirmetallic salts, to temperatures of about 200 to 250 Centigrade. Byemploying, for instance, ortho-chloro-benzoic acid the process takesplace according to the following equation:

COOH I Ortho-OJI, +H N.GH COOHE OOOH OltllO- NH. OH OOOH.

Ortho-brombenzoic acid may also be employed instead ofortho-chloro-benz'oic acid.

Example: One hundred parts, by weight, of ortho-ch'loro-benzoic acid (orthe equivalent quantity of ortho-brombenzoic acid) and fortyeight partsof glycocol in form of their alkali salts are dissolved together inwater. This solution is evaporated to dryness, preferably in o-acuo, andthe mixture of the salts thus obtained is thoroughly dried at 100 to 120Centigrade. The dry mixture is then heated for some hours to about 220Centigrade. The product when cold is dissolved in Water. The solution isfiltered, if need be, and has added to it an excess of hydrochloricacid, where-- upon the phenylglycin-ortho-carboxylic acid separates.This acid may be separated from any ortho-chlorobenzoic acid stillpresent by treatment with chloroform. It is then purified bycrystallization from Water containing hydrochloric acid.

The phenylglycin ortho carboxylic acid thus obtained has the propertiesdescribed by Mauthner and Snida, (Wiener Monatshefte I25, 728,) yieldingwhen heated with caustic alkalies the known indigo reaction of Herracidthus formed in the manner above described.

In testimony that we claim the foregoing as our invention we have signedour names in presence of two subscribing witnesses.

BENNO HOMOLKA. FRIEDRICH HUBNER.

Witnesses:

HEINRICH HAHN, ALFRED BRIsBoIs.

